1. Field of the Invention
The present invention relates to chemical and physical treatment of hard-rock ores to recover uranium and zirconium compounds.
2. Discussion
Techniques exist for extracting uranium from hard rock ores. However, no methods currently exist for recovering other metal values, such as zirconium, in high purity (xe2x89xa798.5 wt. %) from uranium-tainted ores, including Caldasite ores.
The present invention provides a method of recovering zirconium values from an ore containing zircon, baddeleyite, and uranium. The method includes contacting the ore with sulfuric acid to produce a liquid phase comprised of zirconium and uranium values and a solid phase comprised of baddeleyite and silica. In accordance with the method, silica is separated from the baddeleyite by dispersing the solid phase in an aqueous basic solution to dissolve the silica. Baddeleyite is further concentrated by contacting the solid phase with sulfuric acid to convert baddeleyite to zirconium sulfate, which is soluble in the liquid phase. To concentrate the zirconium values, the method provides for contacting the liquid phase with an organic phase in order to extract the zirconium and uranium values into the organic phase, which is contacted with an aqueous solution to strip off zirconium values. Generally, the method provides for contacting either the ore or the baddeleyite with sulfuric acid at a temperature between about 135xc2x0 C. and about 255xc2x0 C., and often at a temperature between about 175xc2x0 C. and 255xc2x0 C.